As can be understood, there are numerous reasons to reduce power consumption of a lighting or other electrical system. The benefits include reduced power costs to the user and benefits to the environment. While it may be desirable to reduce an electrical system's power consumption, it is preferred to not reduce or hinder operation of the electrical system. By way of example, a lighting system's power consumption can be reduced by dimming the lights, but reducing power consumption may undesirably reduce the light output of the lighting system. The lighting system was likely installed and designed for a predetermined amount of input power or voltage and hence, reducing the amount of the voltage defeats the purpose of the lighting systems.
It is known, however, that certain types of electrical systems can be provided less power without hindering operation. In the case of lighting systems, it is known in the prior art that high intensity discharge (HID) and fluorescent lighting systems can be operated at a lower voltage after operation for a short time at full power. Power savings through dimming can be realized without an appreciable amount of reduced light output. For example, the change in light output can not be detected by the human eye.
While it is desirable to reduce power consumption in lighting or other electrical systems by reducing the voltage supplied to the systems reliable and dependable, operation must be maintained. In one example installation, HID and fluorescent lighting can be installed in a parking lot, parking garage, or building interior. If the power saving systems malfunction, the lights can be rendered inoperable. A malfunction could create an undesirable and dangerous environment. In other instances, the lights can facilitate business transactions. If the lighting system illuminates an automobile parking lot or the interior of a business establishment, an inoperable lighting system could result in lost profits and a reduction in market share. Customer goodwill and reputation can also be damaged.
As a drawback to prior art systems, the combination of running a load at voltage levels near the minimum voltage level for continued operation and use of the voltage modifying devices, such as a transformer, can create unreliable operation. In some instances unwanted signal components are introduced into the power signal which disrupt operation. In the case of power reduction system configured with transformers, signal components can be introduced that disrupt desired operation. In addition, the power reduction systems generally lack any fail safe mechanisms to protect the system and ensure reliable operation.
Thus, a need exists for a power reduction system which effectively reduces voltage levels to a desired level for a period of time while ensuring consistent and reliable operation of an associated load. In addition, a need exists for the reduction and/or elimination of unwanted signal components which can be introduced during the voltage reduction operation while consistent operation of the system is maintained.